JPH01279932A - Molding and its production - Google Patents

Abstract

PURPOSE:To obtain a molding having a high carbon fiber content and improved in bending strength and modulus by laminate-molding unidirectionally doubled carbon fiber prepregs having a low resin content so that the decrease in the resin content due to resin flow may be very small. CONSTITUTION:Unidirectionally doubled carbon fiber prepregs having a resin content of 19-27wt.% are laminate-molded so that the decrease in the resin content due to resin flow is within 2wt.%, desirably, 1wt.% to form a carbon fiber-reinforced thermoplastic resin molding having a carbon fiber content of 67-75vol.%. According to the above process, a molding having a sufficient interlaminar shear strength and a strength and a modulus corresponding to Vf. can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel molded article using unidirectionally aligned carbon fiber prepreg and a method for manufacturing the same.

[Conventional technology]

Oriented carbon fibers are impregnated with a thermosetting resin to form a unidirectionally aligned prepreg, and then multi-layered and hardened, the carbon fiber-reinforced resin molded product can be used for industrial materials such as leaf springs and honeycomb structure materials, or for fishing rods and pull shafts. It is widely used in sports and leisure equipment such as Furthermore, recently it has been used as a component for aircraft, automobiles, ships, etc.

The performance of the carbon fibers used has improved significantly in recent years, and polyacrylonitrile carbon fibers have already reached 600 kg/■=
High strength and high elongation type with tensile strength exceeding 500 kp/W" and
High-strength, high-elasticity types with a tensile modulus of 50 ton/■2 have been developed and fabricated, and the performance requirements for molded products obtained by using them as reinforcing fibers have also improved as the performance of raw carbon fibers improves. Performance is increasing.

The first step in improving the performance of carbon fiber-reinforced resin moldings was to improve the interfacial adhesive strength between carbon fibers and matrix resin.

Regarding this point, a large amount of research and development has been carried out energetically over the past ten years, and it has now been achieved at a fairly high level using electrolytic oxidation methods, gas phase oxidation methods, etc. However, in recent years, no significant progress has been seen in this technology, and there is little prospect that properties such as interlaminar shear strength will be further improved in the near future.

In addition, there have been several reports in the past that modification of the matrix resin contributes to improving the performance of carbon fiber-reinforced resin molded bodies (e.g., Japanese Patent Application Laid-Open No. 57-41612). In the case of resin-based materials, it is not possible to expect much improvement in the performance of the molded product itself by modifying the resin. However, according to the experience of the present inventors, the curing temperature is generally high;
A matrix resin with a high crosslinking density (higher stiffness) exhibits higher one-way shear strength and bending strength.

[Problem that the invention seeks to solve]

In any case, with conventional technology, despite recent remarkable improvements in the performance of carbon fiber itself in combination with matrix resins of the same curing temperature grade, this does not lead to improvements in the performance of composite material molded bodies used as reinforcing fibers. is the current situation. A particular problem is that improving the tensile strength of carbon fiber does not contribute to improving the bending strength or compressive strength of the molded product using it as a reinforcing fiber, and no matter how strong the carbon fiber is, if the matrix resin is the same, This means that no improvement in bending strength or compressive strength beyond a certain level is observed even when using .

Figure 1 shows bispheno-/I/A type epoxy resin It! for four types of carbon fibers with different tensile strengths. (Curing temperature 130
3 is a graph showing the relationship between the three-point bending strength of a nine-direction oriented fiber-reinforced resin molded plate made in combination with the carbon fiber strand strength used therein. The measurement conditions are specimen dimensions: fiber axial length 100cm x width 1
〇-×thickness 2■, span length = 80m, span thickness ratio = 4
0, nose and support radius = 1141nch.

Crosshead speed 5/min, measurement environment 21℃
504R)! It is. Also, the measured value is fiber volume content 607
01 conversion value was used.

As is clear from FIG. 1, the bending strength of even carbon fiber specimens with high strand strength is approximately 180 to 9/-, and does not exhibit any higher value.

In addition, when observing the fractured specimens after these measurements, the specimen in Figure 1 shows fracture from the tension side, but B%O and D, which have high strand strength, all indicate fracture from the compression side. . This shows that even though the tensile strength is improved, the compressive strength is not improved, so that the bending fracture becomes the rate-limiting compression fracture. The reason for this is thought to be that in the case of compression, complex factors such as the buckling of the fibers, the adhesive strength between the fibers and the matrix resin, and the elastic modulus of the matrix resin act, and fracture occurs through a mechanism different from that in tension. .

The fact that it is not possible to obtain a product with high bending strength means that when trying to actually use a carbon fiber reinforced resin molded product, it cannot be used in almost all applications, whether it is a leaf spring, a fishing rod, or a boat. Considering that the form is bending deformation and bending fracture, this can be said to be an extremely serious problem.

On the other hand, another major problem when trying to use carbon fiber-reinforced resin molded bodies as industrial materials or sports and leisure equipment is that when trying to obtain molded bodies with high elasticity or high rigidity, it is generally extremely expensive. High elasticity carbon fiber must be used, and generally speaking, the higher the elasticity, the greater the reduction in compressive strength and bending strength.

In order to improve the elastic modulus at the same time as improving the bending strength of such a carbon fiber-reinforced resin molded product, the inventors increased the carbon fiber content in the molded product to a greater extent than the generally applied level. After various studies, we have arrived at the present invention.

In conventional technology, attempts to increase the carbon fiber content in the molded product include: - Lowering the resin content at the stage of intermediate materials such as prepreg - Sucking out the resin with prepreg cloth or squeezing it out with excessive pressure during molding Although it is generally carried out by
As reported in Vol. 1, No. 2, pp. 24-28 (1981), in a molded article with a high fiber content, when the fiber volume content (hereinafter abbreviated as Vf) is 65-67 vo1% or more, the interlayer The shear strength decreased rapidly, and the bending strength also decreased significantly due to the rate-limiting interlaminar fracture. Therefore, when puffiness is taken into account, carbon fiber reinforced resin molded bodies with V'f = 65 mm or more are considered to be physically dangerous, and molded bodies with a Vf higher than this have hardly been studied. , and there are no examples of its practical application.

The present inventors have found that the resin weight content of existing commercially available unidirectionally aligned carbon fiber prepregs is the lowest at approximately 30 wtl, and in molding that suppresses resin flow, the molded product can be reduced depending on the carbon fiber density and resin density. Vf is at most 63-64
Focusing on the fact that with conventional technology, it is impossible to obtain a molded product with Vf of 65 vol% or more unless the resin is sucked out using a bleeder cloth or squeezed out by pressure, we focused on the fact that the resin transfer during molding was It has been found that the fiber distribution or dispersion state in the high Vf molded article becomes non-uniform and the interlaminar shear strength and bending strength are significantly reduced.

[Means for solving problems]

The gist of the present invention is to provide a unidirectionally aligned carbon fiber prepreg with a significantly lower resin content than those conventionally used;
Specifically, a carbon fiber-reinforced thermosetting resin molded body with excellent mechanical properties, using a unidirectionally aligned carbon fiber prepreg with a resin content of 19 to 27 wtl as a molding material, and a method for manufacturing the same, include a resin content of 19 to 27 wtl. When laminating unidirectionally aligned carbon fiber prepregs of ~27wtl to form a laminate, the stacking and molding are performed so that the decrease in resin content due to resin flow is within 2wt4, preferably within 1wt4. The present invention relates to a method for forming a molded article of carbon fiber reinforced thermosetting resin having a fiber volume content of 67 to 75 vol%.

According to the present invention, it is possible to obtain a carbon fiber reinforced thermosetting resin preformed body having sufficient interlaminar shear strength, bending strength and elastic modulus commensurate with Vf. The prepreg used in the present invention is preferably a solvent-free hot melt impregnated prepreg.

This is because microvoids are observed in the molded product due to residual volatile matter in the prepreg prepared by diluting and impregnating with a solvent.

In addition, even with the hot melt impregnation method, a one-tension method in which a resin film is formed on only one side is preferable to the so-called double film method, in which a resin film formed on a release paper is impregnated by applying it from the top and bottom surfaces of a carbon fiber bundle sheet. A single film method in which a paper pattern is applied and impregnated is preferable.

In the double film method, in order to obtain a prepreg with a low resin content as in the present invention, it is necessary to accurately form a very thin resin film on the release paper, although it depends on the date of the prepreg.

Furthermore, even if a resin film is formed, since the resin is impregnated from above and below, a large amount of unimpregnated portion remains in the center of the prepreg, which may cause voids after molding.

However, in conventional solvent-free hot-melt impregnation type prepregs, it is extremely difficult to impregnate resin when the resin weight content is less than 27 wtl, and there are no prepregs available on the market. Therefore, the present inventors investigated the appropriate viscosity level of the impregnated resin in order to obtain a prepreg with such a low resin content.

FIG. 2 is a schematic diagram of the prepreg manufacturing equipment used for the impregnation study.

In Figure 2, 1 is cream, 2 is a comb, 3 is a feed roll, 4 and 5 are opening pars, 6 is a release paper coated with epoxy resin, 7 is a dancer row # for tension control, and 8 is a A polyolefin film μ for the cover, 9 a plate heater for preheating and impregnation, 10, 11.12 a heating nip row μ for impregnation, 15 a copper film winding device, and 14 a prepreg winding device.

Carbon fiber tow was prepared in this device so that the fiber date was 10 Of/m'', and impregnation studies were conducted by varying the viscosity of the epoxy resin used to coat the release paper.The results are shown in Table 1. For convenience, the resin viscosity is 90±(L2
The lowest viscosity measured using a rotational viscometer at °C was used. As is clear from Table 1, the resin weight content is 50 wt4.
At the resin viscosity level where impregnation and tack properties were good for prepregs with a degree of T, impregnation becomes extremely difficult as the resin weight content decreases to 27 vc% and even 19 wtl. However, as the resin viscosity Vpay is lowered, it becomes possible to impregnate prepregs with lower resin weight contents. In addition, prepregs with a resin weight content of 30 wtl had too strong tack, which caused problems in workability.Even with low viscosity level prepregs, the problem is that the tackiness decreases as the resin weight content becomes lower. It disappears. When the resin weight content is less than 25wt4, even if a resin with a low viscosity level is used, a resin layer will not be formed on the surface layer of the prepreg, resulting in almost no tack and a dry tack state, making it difficult to bond during lamination. However, it can be heated with an iron or the like during lamination, or it can be used in combination with prepreg that has a high resin content and tack.

In addition, in prepreg with such a low resin weight content,
With normal release paper for prepreg, the adhesive strength between the prepreg and the release paper is insufficient, and the workability may become warm. However, release paper with higher release properties by changing the type of release agent and processing method is used. This can be solved.

The present inventors evaluated the release properties of the release paper using the 180° peeling method of the nine adhesive tapes shown in FIG. 25 wm width is suitable, preferably 350-500 f/25-width.

Measurement of peeling force The ring breakage was performed at 21°C, 504RT1, and the nine standard adhesive tape used for measuring the peeling force was 5co manufactured by Sumitomo 3M ■.
tch Single-sided adhesive tape ◆25o.

The peeling speed by the tensile tester was 50 m/min, and the other measurement conditions were in accordance with J-Ko S Z 0237 to evaluate the peeling force.

The peeling force of the prepreg supporting surface of currently commercially available prepreg release paper measured by the same method is 50 to 250.
It was f/25cm wide. Peeling force is 600y/2s
(2) If the width is exceeded, the peeling becomes too heavy, and even with the prepreg having the resin content according to the present invention, it becomes difficult to pierce the release paper.

However, if the resin viscosity becomes too low, the strength of the prepreg in the direction perpendicular (90°) to the fiber axis direction of the prepreg will be lost, and tearing will easily occur in the lateral direction, resulting in poor workability.

In any case, if you select an appropriate resin viscosity, you can optimize the release properties of the release paper and adjust the resin weight content by 2 or more depending on the method of use.
It is possible to put it to practical use even with prepregs with low V-gin content of 7wt4t or lower.

After confirming through the study shown in Table 1 that it is possible to produce prepreg with a resin weight content of 27 Wt or less by using a resin with an appropriate viscosity level, Approximately 2-directional unidirectional soundboard was formed using prepreg, and a rectangular specimen with a length (fiber axis direction) of 100 cm x width of 10 cm was created, and the interlaminar shear strength was measured by three-point bending test and short beam method. A test was conducted. Also, for comparison, the resin weight content was 29vrt4 and about 35w.
A similar specimen was prepared for the prepreg of 100 t/@" carbon fiber and used for measurement. As for carbon fiber, both had a tensile strength of 360 kg/w" and a tensile modulus of 24 ton/w". EBOKI V It QW is mainly made by modifying and thickening bispheno-A/A diglycidi ether type epoxy with diaminodiphenylsulfone, and also dichloropheni dimethyl urea is used as a curing catalyst. Bisphenol A or bispheno-F diglycidyl ether type epoxy v (n = o to 1) was used as a diluent.Resin viscosity was adjusted by adjusting the degree of modification of the main component epoxy and the amount of diluent added.

The molded plate was created by combination molding. The resin flow was adjusted by two methods: 1. Layering nylon taffeta and Gutsufu Iperbleeder cloth on top and bottom of the stack, and changing the molding pressure.

The results of the three-point bending test and the Va-) beam method interlaminar shear strength test are shown in Table 2.

As is clear from the table, high Vf of 67m014 or higher
In the test specimens in which resin flow was suppressed during molding, there was little decrease in interlaminar shear strength, and both bending strength and bending modulus tended to increase in proportion to Vf.

On the other hand, prepregs with resin weight content of about 29 wt or about 53 wt4 that cause a lot of resin flow and achieve high Vf have lower interlaminar shear strength and high bending strength despite high Vf. It is not a value.

Furthermore, the greater the amount of resin flow at that time, the greater the decrease in interlaminar shear strength (the bending strength also shows a lower value).

From Table 2, the resin weight content is 27 wt, and in the case of kelp V-tension molding for prepregs of '6 or less, the resin weight content is 15 to 9/c.
- At a pressure of about 100 lbs., the decrease in resin weight content due to resin flow remains at about 1wt4, and the decrease in interlaminar shear strength is small. If the decrease exceeds about 2 wt4, a considerable decrease in interlaminar shear strength will occur.On the other hand, even if the resin flow is caused by a bleeder cloth, it will be 2 to 4 wt4.
When t4 occurs, the interlaminar shear strength decreases significantly. The decrease in interlaminar shear strength due to such resin flow reduces the Vf of the molded product.
However, it was relatively small and did not pose a problem for items below 65 vox Sorry.

This is because for molded products in the high Vf region, such as those exceeding 67 vol, if a molding method that increases resin flow is adopted during molding, the resin flow will not occur uniformly throughout the molded product, for example, in the case of comb V-tension molding. In this case, resin transfer occurs selectively from the ends in the fiber axial direction, or from the surface layer in contact with the cloth when using a pulley cloth, and because the amount of resin is originally small, resin loss between single fibers, This is thought to be due to the intensive generation of microvoids and the like, which deteriorate properties such as interlaminar shear strength, bending strength, and compressive strength.

From the experimental results shown in Table 2 and other studies, the limit for reducing the resin weight content to avoid deterioration of the physical properties of the molded product is about 2 wtl or less, preferably 1 wt4 or less.

When molding fishing rods, golf shafts, etc. by the tape wrapping method, it is generally difficult to control the resin flow, and it is particularly difficult to flow a large amount of resin during molding. For example, using a prepreg with a resin weight content of 30 wt4, Vf
= 67 It is difficult to achieve VO1% or higher. Even if molding is possible, the resin will flow unevenly, resulting in a decrease in interlaminar shear strength and bending strength. Resin weight content according to the invention 19-27
In molding using wt4 prepreg, carbon fiber density,
Although it depends on the resin density, a high Vf molded product of 67 vol or more can be easily obtained, and high bending strength and high bending elastic modulus can be expressed in proportion to Vf.

In addition, if an epoxy resin with higher resin rigidity after curing than bispheno-A/A diglycidi-ether type epoxy resin is used, in addition to originally having high bending strength, the Vf of the present invention
Due to this effect, even higher bending strength can be developed.

However, there are limits to high Vf.

Even if molding is carried out with the resin flow kept low, if Vf exceeds about 75 vol, the interlaminar shear strength will drop significantly, leading to a drop in bending strength.

Therefore, if a prepreg with a resin weight content of less than about 194 is used, no matter how much resin flow is suppressed, the Vf of the obtained molded article will exceed 75 vol%, which is undesirable.

A more preferable carbon fiber volume content of the molded article of the present invention is 69
~75 vol%.

If Vf becomes too high, even if the resin flow during molding is suppressed, single fibers will come into direct contact with each other without the matrix resin intervening, and so-called void nests in which microvoids are connected will occur frequently.

〔Example〕

The present invention will be specifically explained below using examples.

Example 1 High-strength carbon fiber (tensile strength 360 kg/-", tensile modulus 24
ton/m") and a V-gin film coated with a 130℃ curable epoxy resin on a release paper with a peeling force of 400 t/2s-width, the resin weight content is 250.
wt sorry, textile date 165? Create prepreg of /-,
In addition to this prepreg, a commercially available ultra-thin unidirectionally aligned carbon fiber prepreg (resin weight content: 57.sv) was used for lateral reinforcement.
tt4, fiber date 27 f/m", 150° C. curable epoxy resin matrix) was orthogonally attached, the fiber axis direction of the former prepreg was set as the longitudinal direction, and the latter prepreg was set as the inner winding direction, and a 10φ Iron mandre/L/
Wrap it 4 times around the polypropylene tape (width 15 m)
) was flopped at a tape tension of 5/15 mm, placed in a curing oven, and cured at 130°C for 2 hours to form a pipe with a length of 600 cm. The resin flow during molding is α5 wt4 as the decrease in resin weight content including the prepreg for lateral reinforcement.
It was within

For comparison, a commercially available unidirectionally aligned carbon fiber prepreg (carbon fiber tensile strength 360kl?/■:, tensile modulus 24 ton/■2, resin weight content s o wt4) was used for comparison.
An ultra-thin prepreg similar to that in the example was adhered to a 130° C. curable epoxy resin matrix, and a 600 m long pipe was formed in the same manner using a 10φ mandrel. Furthermore, the decrease in resin weight content due to resin flow during molding of this pipe is also α5 wt4.
It was within

A four-point bending test was conducted on these pipes, and the bending strength and bending modulus were measured. The measurement results are shown in Table 3. Furthermore, FIG. 3 shows a schematic diagram of the measuring jig used for this measurement. In the figure, 1 is a movable indenter, 2 is a fixed indenter, 3 is a sump fi10 IFRP pipe, and 4 is an inner diameter of 11.5 cm and a thickness of 2-1 width 10 installed to prevent stress concentration at the indenter.
1 shows a metal ring. The measurement conditions were: movable indenter span length 500cm, fixed indenter span length 150cm, crosshead speed 5cm/min, measurement atmosphere 21℃5C1!
It was carried out at RH.

As is clear from Table 3, the pipes formed by the method of the present invention are more bendable than the pipes formed by the conventional method using commercially available prepreg, despite having the same weight and wall thickness. A product with a strength and flexural modulus of approximately 154 higher can be obtained.

Example 2 High strength, high elasticity carbon fiber (tensile strength 420' to 9/ss'', tensile modulus 40 tons) was prepared in the same manner as in Example 1.
/■8, density 1. a 1y/♂) and a 130°C curing epoxy resin, the resin weight content is 25 wt.
4. A prepreg with a fiber date of 152 t/density 1 was prepared, and a commercially available ultra-thin unidirectionally aligned carbon fiber prepreg (resin weight content 57.5 wt4) was added to this prepreg for lateral reinforcement.
After orthogonally pasting the fibers (27t/ml, 130°C curable epoxy resin matrix), the former prepreg's fiber axis direction is the longitudinal direction, and the latter prepreg's inner winding direction, and 4 Wrap the polypropylene tape (width 15cm) around the circumference with a tape tension of 3.
Wrap with Yu/15as and put in a curing oven at 130℃
It was cured for 2 hours to form a pipe with a length of 600 square meters.

The resin flow during molding was α5 wt4 or less as a decrease in resin weight content including the prepreg for lateral reinforcement. Further, after the test, the outermost layer of the pipe was beer-filled and the resin weight content was determined by acid decomposition method, and the decrease was 1wt4 or less in all cases.

In addition, as a comparison, a commercially available unidirectionally aligned prepreg (
Tensile strength of carbon fiber: 33okp/■2, carbon fiber density: 1.
A similar ultra-thin prepreg was attached to a 88 f/ctyt (resin weight content: 33 vtt6, fiber date: 13997 m, epoxy resin matrix cured at 130° C.), and a pipe with a length of 600 cm was formed using the same method.

A four-point bending test was conducted on these pipes in the same manner as in Example 1, and the measurement results are shown in Table 4.

Also, the tensile modulus used in this measurement was 40 ton/-1
Resin weight content 25wt4 using high modulus carbon fiber
Test specimens with a length in the fiber axis direction of 100 cm, 10 ml, and a thickness of 2 mm were made from the prepreg and a commercially available ultra-high modulus carbon fiber prepreg used for comparison using a comb V-tension mold, and the span length was 80 cm. Span:thickness ratio 40:1,
Nose extending port A/rabbit 1nch, crosshead speed 5 wm/min, measurement environment is 21
A three-point bending test was conducted at 504 RH and the results are shown in Table 5.

In addition, Vf in Table 5 was calculated by the following formula using the resin density (1,2597 cm'') and carbon fiber density obtained by determining the fiber weight content by acid decomposition method.

H (where PR = resin density, ρOF = carbon fiber density, W
f = fiber weight content) As is clear from Table 4, even if the weight, wall thickness, and bending modulus are the same, the bending strength of the pipe according to the present invention is 40 times higher than that of the comparative example. is obtained. This means that in order to obtain a pipe with the same bending modulus, even if the modulus of elasticity is low when viewed at the same Vf, the bending strength is originally high. This is because the strength can be improved. This is clear from the results of the three-point bending test shown in Table 5. In this case, the same Vf (60vo
The difference in bending strength is approximately 23 #I in terms of 1%), but v
Without f conversion, the example of the present invention has a measured value of bending strength that is approximately 404 times higher than that of the comparative example with almost the same modulus of elasticity.

Furthermore, in Table 4, the weight of carbon fiber used in the longitudinal direction of the pipe according to the present invention is approximately 104, which is greater than that of the comparative example, but due to factors such as firing cost, the tensile modulus of elasticity used for the pipe according to the present invention is generally determined as the market price. 40 ton/■ low grade fiber has a tensile modulus of elasticity of 4 used in the comparative example.
The pipe according to the present invention is significantly cheaper than carbon fiber of 6 ton/■on/■do, and can be manufactured at a sufficiently lower cost than the pipe of the comparative example.

Comparative Example 1 In Example 1, a prepreg with a resin weight content of 50 wt4 and a fiber basis weight of 16,517 m'' was created, and as in Example 1, extremely thin carbon fiber prepreg was pasted orthogonally to a 10φ
To wrap the iron mandrel four times, use a polyester tape (15-width) coated with G1M agent on one side in the direction in which the release-treated surface touches the Deride V surface, and use a tape tension twice that of Example 1.6) After flapping with c9/15■, hardening oven at 150
C. for 2 hours to obtain a pipe with a length of 600 mm. Note that the resin flow during pipe molding was approximately 6 vt% as a reduction in the overall resin content including the ultra-thin prepreg.

A four-point bending test was conducted on this pipe in the same manner as in Example 1. The results are shown in Table 6.

Also, after bending and breaking, the outermost layer of the pipe (the layer with the fiber axis in the longitudinal direction) was brewed with a cutter knife and the resin weight content was measured, and it was approximately 19 wt'! It was made.

That is, the amount of decrease in resin weight content due to resin flow in the outermost layer was as large as 11 wt4, indicating that resin flow occurred quite intensively in the outermost layer.

As is clear from the results in Table 6, high Vf pipes formed using the prior art have a high elastic modulus but a low bending strength.

[Brief explanation of the drawing]

Fig. 1 is a graph showing the relationship between the bending strength of the formed plate and the tensile strength of the carbon fiber strand, Fig. 2 is a schematic diagram of the prepreg manufacturing equipment used in the present invention, and Fig. 3 is a pipe four-point bending test measurement device. FIG. 4 is a schematic diagram showing a measuring device for measuring the releasability of release paper. Tai 1 Kanaη Mata Drashito “Tensile strength, shoulder L (k3/rrrn'n bird 2
Illustration 3 I21 Tame 4 indentation ↑ Procedural amendment 1, indication of the case Patent Application No. 1-10267 2 Name of the invention Molded object and its molding method 5 Person making the amendment Relationship with the case Patent applicant 2 Kyobashi, Chuo-ku, Tokyo 3-19-chome (603) Mitsubishi Rayon Co., Ltd. President Yatabe Nagai 4, Agent Address: 2-3-19 Kyobashi, Chuo-ku, Tokyo 104 The description has been amended as follows. 1) After “Interlaminar shear strength” on page 3, line 12, “(Work Length 8 days)
” is inserted. 2) Delete page 4, line 9, "It is considered as a reinforcing fiber." 3) Insert ``Three-point bending test'' after ``Note'' on page 5, line 3. 4) On page 14, lines 11-12, add the following paragraph after "Implemented." “The conditions for the interlaminar shear strength test are length (R off-axis direction) 12
m x width 10 mm x thickness 2 shoes, span length 10 order, span:thickness ratio 5:1, nose and support radius 1/81 nch
The crosshead speed was 5 W/min, and the measurement environment was 21° C. and 50 RH. ” 5) On page 15, line 9, “Breeder” is corrected to “Breeder”. 6) Page 23, line 14, “Insert “width” before 10aml. 7) After "bending test" on page 23, line 18, insert "Also, perform an interlaminar shear strength test under the same measurement conditions as the interlaminar shear strength (LSe) in Table 2."

Claims (1)

[Scope of Claims] 1. A carbon fiber-reinforced thermosetting resin molded article, characterized in that a unidirectionally aligned carbon fiber prepreg having a resin content of 19 to 27 wt% is used as a molding material. 2. The molded article according to claim 1, which is a unidirectionally aligned carbon fiber prepreg supported on the release surface of release paper having a release surface whose peeling force is controlled to 300 to 600 g/25 mm width. 3. The molded article according to claim 1, wherein the carbon fiber content is 67 to 75 vol%. 4. The molded article according to claim 1, wherein the molded article is a pipe. 5. One-way aligned carbon fiber prepreg with a resin content of 19 to 27 wt% is laminated and molded so that the decrease in resin content due to resin flow is 2 wt% or less, so that the carbon fiber volume content is 67 to 75 vol. % carbon fiber-reinforced thermosetting resin molding method.